Kefersteinia Nova Isthmii Americani Australis Cum Generis Synopsi

A new species of Kefersteinia (Orchidaceae) from the southern region of the Central American isthmus is described and illustrated, and its affinities with K. elegans are discussed. In Panama, Kefersteinia luteola was previously misidentified as the Colombian K. elegans, but the new species appears to be restricted to the Cordillera de Guanacaste and Talamanca in Costa Rica and Panama. Among Kefersteinia species, K. luteola is distinguished by its small yellowish flowers, broadly extensively excised lip with a depressed laminate, trullate callus, and a column recognized by large, triangular, rounded wings with subciliate margins. The most similar species is Kefersteinia elegans, from which it differs in plant and flower size, with subringent sepals and petals, a sessile entire lip, and minutely glandular-ciliate wings of the column. A synopsis of the genus Kefersteinia is presented, and the species grouped according to their overall similarity.